The Study Of Screening Aberrant Methylated Gene In The Mouse Model Of Alzheimer’s Disease

Alzheimer’s disease is a chronic progressive neurodegenerative disorder,which primary histological features are the senile plaques and neurofibrillary inthe cerebral cortex and hippocampus. And so far, the pathogenesis ofAlzheimer’s disease is not clear. With the further research of DNA methylation,scientists have found several aberrant methylated genes related withAlzheimer’s disease, such as APP、 PS1、 PS2. Are there more aberrantmethylated genes involved in the pathogenesis of Alzheimer’s disease? Thisstudy will analyse the methylation status of genome of APP/PS1double-transgenicgene mouse model of Alzheimer disease by using methylated DNAimmunoprecipitation on chip, in order to find more relevant aberrantmethylated genes.We collect three APPswe/PSΔE9double-transgenicgene mouses model ofAlzheimer disease and three C57BL/6J mousse, extract genomic DNA frombrain, With MseI enzyme digestion to random DNA fragments in size about500bp, purificate the DNA product meanwhile, one part of product as Inputsample, the other as IP sample. Immunoprecipitation of methylated DNA wasperformed using mouse monoclonal antibody against5-methylcytidine andmagnetic beads coupled anti-mouse IgG. Immunoprecipitated DNA was elutedand purified by phenol chloroform extraction and ethanol precipitation. Afteramplificated, Input DNA and IP DNA were labeled with Cy3-and Cy5-labeledrandom9-mers respectively, and hybridized to NimbleGen arrays, Scanningwas performed with laser scanner and analysing by related software, so that weget the aberrant methylated genes.According to analyse the result of the MeDIP-chip by NimbleScan and SignalMap software, we get the log2Ratio, the bigger the value, the higher thestatus of DNA methylation. we test the p-value meanwhile. At last,2347aberrant methylated sites were screened, which involving485genes, and theydistribute in different chromosomes. And analyse the function of aberrantmethylated genes by online KEGG database.we get aberrant methylated genes of the double-transgenicgene mouse byusing MeDIP-chip, which lays a solid foundation for the subsequent validationexperiment, provides a clue for Alzheimer’s disease in human. It is promising toestablish genomic DNA methylation map for understanding the mechanism ofAD, as well as the diagnosis and treatment of Alzheimer’s disease.